It's commonly claimed that no one paid the 70% rate. But do you have any evidence that that is true? It feels like one of those "facts" that has no sourcing.
Here you go [1]. Most high income earners in the 50s paid about 42%. It’s hard to squeeze income much more than that without the income going somewhere else. Historically speaking.
That's not what that says. The graph that tops out at 42% is talking about the effective tax rate, not marginal. It's perfectly possible that some people had part of their income taxed at 70%, but their effective tax rate was 42%. That's just how marginal tax brackets work.
It entirely possible but no one was paying the 91% rate. The broader poor was that these rates weren’t effective. Reported income is highly elastic, according to work by Saez et. al.
As that link points out, the majority of the high earners (top 1%), which were averaged to get to 42%, did not even reach the highest tax bracket. The vast majority it turns out. The highest tax bracket applied to less than 2% of the top 1%.
Who likely didn’t pay that as they had plenty of tax avoidance strategies, not unlike the ultra-wealthy today. The apocryphal story I read some years ago was that these rates were cooked up to make it seem like the wealthy were shouldering the burden of WWII rather than profiting from it.
